Counterfeit makeup isn't always easy to spot, but as a general rule of thumb - if it's too good to be true, it probably is.

The Los Angeles Police Department says it confiscated counterfeit makeup that tested positive for high levels of bacteria and animal waste. The packaging appears authentic, but the prices are much lower than normal.

Detective Rick Ishitani told KABC companies must meet the expensive duty of meeting safety standards while makers of bootleg product don't. Los Angeles Police Capt. Marc Reina wrote on his Twitter account next to images of police looking at vendors in The Santee Alley. However, when you see your favorite products offered at 50% to 75% off (and not directly from the brand retailer), this is most likely a counterfeit. "SO GROSS! Never buy counterfeit products!"

The police arrested six people in relation to the investigation.

Because these products are often being formulated in unsanitary and unregulated environments (like people's bathrooms or garages) they can get contaminated easily.

There have been reports that some fake lip kits also have glue in them.